Switch for use in telephone systems



A ril 10, 1934. F. DURING ET AL 1,954,121

SWITCH FOR USE IN TELEPHONE SYSTEMS FiledMay 4, l952 5 Sheets-Sheet lKonrad 1 1151 151- ,April 10, 1934.

F. DORING ET AL 1,954,121

SWITCH FOR USE IN TELEPHONE SYSTEMS Filed May 4, 1932 5 Sheets-Sheet 2April 10, 1934. F. DURING ET AL SWITCH FOR USE IN TELEPHONE SYSTEISFiled Kay 4. 1932 5 Sheets-Sheet 3 April 10, 1934. F. DORING ET ALSWITCH FOR USE IN TELEPHONE SYSTEMS Filed May 4, 1932 5 Sheets-Sheet 4 Tu mcrs 1 1-1 1T2 Day-m Konrad TTuuur April 10, 1934. Q m ET AL 1,954,121

SWITCH FOR USE IN TELEPHONE SYSTEMS Filed May 4, 1932 5 Sheets-Sheet 5FP'TIE Biz-in Konrad M11111 r fiim '7 to attain the required settingspeed which may Patented Apr. 10, 1934 SWITCH FOR USE IN TELEPHONESYSTEMS Fritz Doring, Berlin-Frohnau, and Konrad Miiller, BerlinSiemensstadt, Germany, assignors to Siemens & Halske Aktiengesellschaft,Berlin-Siemensstadt, Germany, a German com- D y Application May 4, 1932,Serial No. 609,142 In Germany May 4, 1931 11 Claims. (Cl. 179-2753) Theinvention relates to switches for communication systems, particularlytelephone systems, and especially to switches the wipers of whichexecute a rectilinear movement. Switches of this type in the telephoneart are named rod switches.

Difficulties are experienced with regard to switches of this type whenthe wipers are to be brought to rest on a definite contact, for example,the called subscribers contact or the contact of an idle line, thedirficulty being to carry out this operation as reliably as otherswitches, such as for example rotary switches. This is mainly due toconsiderable power being required for a rectilinear setting movement inorder from the wiper to the complete range of contacts to be brushed,but only a part thereof.

The smallest possible movable mass may be utilized if the movable memberof the device (i. e. the armature) driven by an electric motor iscoupled direct to the power transmission devices (i. e. the spindle)which transmit the movement to the wiper carrier.

An embodiment of the switch arrangement according to the invention isfully described in conjunction with the accompanying drawings.

Fig. 1 represents a side view of the switch in which the double sidedcontact of the switch is shown in section.

Fig. 2 shows a view of the switch.

Fig. 3 a view of the said switch seen from above.

Fig. 4 the cam actuated switch contacts seen from above and arrangedbeneath the motor.

Figs. 5 to 10 inclusive illustrate various views of an embodiment whichdemonstrates the method of exchanging spindle or guide rods.

Fig. 11 shows a section of a rectangular guide rod and the manner inwhich it has been arranged.

Figs. 12, 13 and 14 show an embodiment of an arrangement at the use ofwhich the size of the contact groups may be determined according torequirements.

Fig. 15 shows the controlling circuits for the switch and itsapplication as a group selector.

The reference numeral 1 represents a device, driven by an electric motorthe construction of which is fully described in co-pending applicationSerial Number 577,672. For this reason the drive mentioned has been onlydiagrammatically shown in Figs. 1 and 2. The armature of the electricmotor is coupled direct to the spindle 2. The threaded wiper carrier 3which is provided with the contact wipers 5, 6 and 7, comprising a pairof springs each, and an interposed fibre disc 4, slides on said spindle.In order to prevent the wiper carrier 3 from taking part in the rotarymovement when the spindle is rotated a guide rod 8 is provided. Thearrangement of the three contact wipers, combined in a set, in themanner illustrated in Fig. 3, shows the central switch Wiper 6 passingbetween the spindle 2 and the guide rod 8 while the other two wipers 5and 7 are arranged on either side of the said rod. Current is applied tothe wipers over the lead 12. Parallel to the spindle 2 or to the guiderod 8 a third rod 20 is arranged, to the approximate middle of which thelead 12 is connected in some suitable manner, for example, by means of aclamp so that the whole weight of the lead 12 only be achieved by meansof larger and more powerful driving devices. Comparatively complicatedand uneconomical auxiliary devices are necessary to handle the movablemembers in rod switches of known types.

The object of the present invention is to produce a rod switch combininga most reliable operation with greatest possible economy in the systemand this is achieved by causing the rotating member of a device drivenby an electric motor of the type disclosed in our co-pendingapplication, Serial No. 577,672 filed Nov. 27, 1931, to actuate powertransmission devices which impart a rectilinear setting movement to theswitch wipers.

Due to the use of the driving device disclosed in the above co-pendingapplication the switch may be brought to rest in a reliable manner evenat very great setting speeds owing to the fact that the total weight ofthe movable mass is comparatively small. The invention, therefore, isparticularly suitable for switches having a single set of wipersbrushing several or all the contact groups instead of separate sets ofwipers for each contact group.

An additional feature of the invention is that a transmission drive isarranged between the power transmitting devices which actuate the switchwipers and the switching means (switch contacts) controlling themovement of the switch. The said transmission drive is so constructedthat it may form contact groups embracing a variable number of contactsof the contact bank. A further means for reducing the size of themovable mass according to the invention, is that the leads to the wipersare suitably connected up within the movable range of said wipers in ornear the centre, with the result that the wiper carrier, when actuated,will not have to carry the total weight of the whole length of leadextending need not be carried when the wipers are actuated. Angularbrackets 9, suitably fixed to the fiat contact bank 10, act as bearingsfor the spindle or for thercd 8. Close to the motor, at the end on theone side of thetrack followed by the returning wiper carrier 3, a set ofcontact springs 21, 22, 23 are disposed on a U-shaped carrier 29. Theset of springs 23, under the influence of a spring 27 is pressed by thewiper carrier 3, against two fixed stops 28 of the wiper carrier,whereas the sets of springs 21 and 22 are actuated by catches 25 and 26fixed to said wiper carrier. These catches pivot on the'screw 24 and areadapted to operate independently of each other in such a manner that theset of springs 21 and 22 are actuated only when the wiper carrier movesforward but not during its backward movement. This arrangement isincorporated in the circuit provided for the switch.

The lower end of the spindle 2 extends beyond the device driven by anelectric motor and in this end carries a small toothed wheel 13 engaginga larger wheel 14 of the same type. The toothed wheel 14 as well as thetwo cam discs 15 which actuate additional sets of contact springs 16 arefixed on the shaft 18 pivoted in the bearing 19. The leads to the setsof contact springs 16 are represented by the reference numeral 17. Thecontact springs 16 are actuated at regular intervals when the spindle 2rotates due to the transmission ratio of the toothed wheels 13 and 14and to the action of the cam faces 15. Thus, it will be found, that thewiper carrier, when actuating the sets of contact springs 16, hascovered a definite distance or in other words, has brushed a definitegroup of contacts 11.

The contact bank 10, shown diagrammatically in section, together withthe fixed contacts 11, forms a suitable multiple bank allocated incommon to a plurality of switches, that is to say, it forms a contactbank of such a type that the multiple connections are found within thebank proper. As will be seen in Fig. 1 the bank 10 forms a double sidedmultiple bank with the object of being able to adapt the back of it alsofor the provision'of switches. The dotted lines in Fig. 2 showdiagrammatically a second switch arranged on the same bank 1. Fig. 4illustrates the form of the cam faces 15 provided and adapted to actuatethe set of springs 16.

Figs. 5 to 10 inclusive give illustrations of an embodiment showing themanner in which the spindle as well as the guide rod may readily beexchanged. The top and bottom bearings for the spindle and guide rod areshown in sectionin Figs. 5 and 8. An angular bracket 30 is fixed to thecontact bank 1 at the upper end of the spindle and is provided with twoholes 31 and 32. A bearing bush 34, partly riveted to the member 33, ispivoted in the bore 31, whereas in the bore 32 is fitted the washer 35,firmly secured be tween the nut 36 and the member 33 by tightening saidnut, and rigidly connected to the guide rod 8. The facility is thusprovided of being able to remove forthwith the member 33 together withthe spindle 2 and the guide rod 8 from the angular socket 30 by drawingit downwardly. As shown in Fig. 7 the member 33 is L-shaped so that therod 20 which serves to fix the lead together with the guide rod 8 formsa rigid frame.

connected to the member 38 by means of the screw 40 and disposed in therecess 41 in the member 3'7. A bush 43 is firmly riveted to the member38 for the spindle 2 and the upper portion of said bush is disposed inthe recess 42 of the member 37. After disposing the bush 34 or thewasher 35 in the upper angular bracket 30 and then pushing the bush 43as well as the washer 39 into the forked recess 41 and 42 of the member37, the screw 44 which is undetachably fixed to the member 37, istightened whereupon all the members are secured in their appropriatepositions;

According to Fig. 11 the guide rod 8 is of square section and is pressedby means of a flat spring 45 against the wall of the opening providedfor the guide rod in the wiper carrier 3. The spring 45 prevents thewipers on said wiper carrier 3 from getting out of alignment.

Fig. 12 shows a plan of a contact arrangement which may be used insteadof the contact arrangement 15, 16 shown in Figs. 1 and 2 and by the useof which the size of the contact groups brushed by the wipers may bealtered according to requirements. The not shown spindle 2 is providedwith a small toothed wheel 46 engaging the toothed wheel 47. Thistoothed wheel 47 in turn actuates the toothed disc 48 which is providedwith pins 49 fixed at various points along the periphery. The pins areadapted to actuate the set of contact springs ,50 suitably fixed on thesupporting base 51. The toothed wheels 47 and 48 rotate in the bearings52 and 53. The contact group to be brushed by the wipers can be alteredeither by exchanging the toothed wheel 48 or by arranging the pins 49individually at various points along the periphcry. of the disc 48 inwhich case the pins are detachably arranged.

Fi 13 shows a front view of the above described arrangement, whereasFig. 14 represents a side view thereof.

If the armature of the device, driven by an electric motor, is coupleddirect to the spindle, the spacing or distance of the contactlaminations on the contact bank is so calculated that it shows adefinite ratio in relation to the pole spacing of the device, driven byan electric motor. The space between each lamination then equals themultiple pole spacing, that is to say, if, for

example, the armature executes a movement from pole to pole, the wipercarrier is moved from one lamination to another due to thecorrespondingly calculated distance which the spindle moves. A toothedwheel transmission upon the ratio of which depends the distance coveredby the wiper carrier may also be disposed between the spindle and therotating member of the device driven by an electric motor.

In many instances it is an advantage to couple the device driven by anelectric motor to the power transmission devices in such a manner that arelative movement between the wiper carrier and the rotating member ofthe device driven by an electric motor may take place when the switch isbrought to rest. This may be effected either by means of a flexiblecoupling fitted between the rotating member of the device driven by anelectric motor and the spindle or else by means of a clutch coupling,that is to say, a coupling which permits the rotating member of thedevice driven by an electric motor to carry out a few more revolutionswhenthe spindle is stopped by mechanical means suchas for example alocking pawl. When a flexible coupling is used between motor and spindlewhen this is to be brought to rest, the armature runs past the statorpole which is energized for the purpose of stopping the motor and, underthe influence of the spring coupling or the energized stator pole,swings backwards and forwards until finally brought to rest opposite thepole.

Instead. of using a spindle as a power transmission device other devicesmay also be provided such as, for example, a chain to which the wipercarrier is fixed, a steel band or some other power transmission deviceknown per se.

A description will now be given of the operation of the switch when usedas a group selector, reference being had for this purpose to Fig. 15.

When the group selector switch shown is seized, relay C energizes overthe c-lead. Relay A responds to impulses transmitted over the a-lead andupon its first operation closes the circuit for relay V which energizesand due to its short circuited winding remains energized for theduration or" the impulse series. Relay V closes a circuit for the motorwhich extends over contacts of relay C. The cam contacts Kw H R and KwZw in conjunction with contacts of relay A control the motor and causethe switch to move at high speed from group to group of contacts. Itshould be noted that the cam contacts Kw H R and Kw Zw correspond to thecontacts 16 shown in Fig. 4. The group control is efiected by the camcontacts in substantially the manner shown in Fig. 11 of our copendingapplication Serial No. 577,672. At the end of the impulsing relay Vreleases and short circuits the damping windings m1 and m2 arranged onthe stator magnets M1, M2 or" the motor. Consequently the switch nowoperates at a lower speed and free hunting takes place over the contactsof a group. The circuit to the motor is now maintained over backcontacts of relays V and P2, from contacts of relay C and off normalcontacts 16. When an idle line is found relay Pl energizes over thec-lead and maintains the coils M1 and M2 energized from earth atcontacts of relay C. Relay Pl also closes the circuit for relay P2 whichenergizes. Relay P2 upon operation, opens the circuit to the motor andswitches through the a and b leads.

If it should happen that all the lines in the group are busy the switchwill be stopped at the end of the grip due to the energization of relayP1 in exactly the same way as if an idle line had been reached.

The release of the switch is initiated upon the de-energization of relayC. Relay 0 upon deenergizing closes a circuit for relay Ru over offnormal contacts is and this relay upon operation causes the reversal ofthe current in the motor and also connects up an alternative earth tocomplete the circuit of the motor in place of the earth disconnected atcontacts of relay C. Due to the reversal in the direction of the currentto the motor the motor rotates in the opposite direction andconsequently the switch restores to normal.

When the switch reaches its normal position the off normal contacts krestore and holding earth is applied to the motor over one of these oiInormal contacts and front contacts of relay Ru in order to bring theswitch to rest. The offnormal contacts is correspond to the sets ofcontacts 21, 22, 23 shown in Figs. 2 and 3. One of these offnormalcontacts is upon restoring opens the circuit of relay Ru which thereuponrestores. The switch is now fully restored to normal and is in acondition for re-operation.

. and. wherein after What we claim is:

1. In a switch structure, wherein a set of movable wipers are arrangedto successively engage the contact sets of a bank of fixed contacthaving been moved into engagem nt with one set of such contacts arelater moved to their initial position by retrograde movement, theprovision of a mechanical arrangement comprising a threaded spindle,equipped with a wiper carrier threaded thereto, of a guide forpreventing rotation of the wiper carrier with the spindle, of nice forrotating the spindle in one direction the distance required toselectively associate the wiper set with any desired one of 5. contactsets and for then restoring the wiper carrier and its wipers by rotatingsaid spindle in the reverse direction.

2. In a switch structure such as covered by the preceding claim,characte ized in that, off-normal springs are arranged to be moved totheir alternate positions consequent to movement of the wiper carrierfrom its normal position.

3. In a switch structure, wherein a set of movable wipers are arrangedto successively engage the contact sets of a bank of fixed contact sets,and wherein after having been moved into engagement with one set of suchcontacts are later moved to their initial position by retrogrademovement, a driving means having a wiper carrier supported thereon fromthe end thereof nearest the bank and having the wipers secured theretoon the opposite end thereof, whereby the over-all depth of spaceoccupied by the wipers and their driving means is maintained at aminimum.

4. In a switch mechanism wherein a set of wipers has access to groups offixed contacts, an electric motor and cooperative gear train for movingthe wipers over the groups of fixed contacts, circuit switching springsfor controlling said motor as required to drive the switch wipers fromone group of contacts to the next each time the motor is energized, andmeans enabling the adjustment of said circuit switching springs to bemodified to accommodate various sized contact groups.

5. In a switch structure, a bank of fixed contacts arranged in avertical plane, brackets fixed to said bank above and below saidcontacts, an operating assembly cooperative with said bank of contacts,and means for removably securing said assembly to said brackets.

6. In a switch structure, a bank of fixed con tacts arranged in avertical plane, brackets fixed to said bank above and below saidcontacts, an operating assembly cooperative with said bank of contactsincluding; a spindle having a wiper assembly threaded thereto, a guidingrod for said wiper assembly, a wiper cord holding rod, and end elementssecuring said spindle and rods in fixed relation to each other; andmeans for removably securing said assembly to said brackets.

7. In a switch mechanism, a bank member having the surface of a plane,sets of contacts protruding from said bank and arranged in a straightline, a spindle mounted on said bank in spaced relation therefrom, awiper carrier threaded on said spindle and equipped with wipers arrangedto engage said sets of contacts, a motor for rotating said spindle inone direction, means for preventing rotary movement of said wipercarrier, with a consequent movement of said wipers rectilinearly throughthe medium of their carrier successively into engagement with saidcontacts, and means for then reversing the direction of rotation of saidmotor to restore said wipers to their initial position.

4. In a switch mechanism, a bank of contacts arranged in a straightline, a set of wipers arranged for movement into consecutive engagementwith the contacts of said bank, means for moving said wipers comprisinga threaded shaft, means for rotating said shaft in one directionvariable distances to bring said wipers into engagement with desiredones of said contacts, and means for then reversing the direction ofmovement of said rotating means to effect the reverse rotation of saidthreaded shaft to effect the restoration of said wipers.

9. In a motor driven switch employing as a source of power a motorequipped with actuating windings and a rotating armature, power trans,-mission devices arranged to impart a rectilinear movement to the wipersof said switch consequent to the rotation of the armature, and circuitswitching members rotatable with the motor armature and employed tocontrol its movement.

10. In a switching mechanism, a set of wipers having a rectilinear pathof movement, fixed contacts successively engaged by said wipers duringtheir course of movement, an electric motor having a rotating member andan associated power transmission device for imparting the specifiedmovement to said wipers, and other members rotated by said motoremployed to control the extent of rotation of the first member and inconsequence the extent of movement of said wipers. I

11. In a switch structure, a bank of contacts, a set of wipersco-operative with said bank of contacts, a threaded spindle equippedwith a carrier for said set or wipers; a motor for driving said spindle,the threads of said spindle having a pitch so calculated with respect tothe spacing of said contacts and with respect to the distance ofrotation of said spindle as determined by the spacing of the pole piecesof said motor that for each stage of movement of the armature of saidmotor the set of wipers are moved from one contact set to the nextadjacent one.

FRITZ DoRING.

KONRAD MULLER.

